The present invention relates generally to brake systems for motorized vehicles, and more particularly to a novel vehicle brake lock system employing a brake lock pedal selectively operable to maintain a primary service brake pedal in an applied brake condition and enable brake release upon actuation of the throttle pedal.
It is a common practice in the the manufacture and use of motor vehicles to employ a parking brake system or arrangement operative to maintain the primary brake system in a braked condition during parking and the like. Such parking brake systems frequently employ means associated with a primary brake pedal to enable selective retention of the brake pedal in its brake applying condition, while enabling release when the operator wishes to effect further movement of the vehicle. See, for example, U.S. Pat. Nos. 1,927,209, 1,985,319, 2,551,743, 2,816,333 and 4,218,936. U.S. Pat. No. 4,310,064 discloses a braking system which is particularly applicable in preventing creep of automatic-transmission wheeled vehicles.
In the case of relatively small size utility and recreational vehicles which undergo frequent stopping, such as golf carts and the like, it is particularly important from a safety standpoint that the vehicle be capable of maintaining a fixed stopped position when disposed on an upwardly or downwardly inclined grade. For example, safety regulations require that certain vehicles, such as golf carts, be capable of maintaining a braked condition on a 30% grade under full load. In the past, such vehicles have frequently employed mechanical braking systems which have the disadvantage that a substantial force must be applied by the operator to the primary brake pedal to effect braking, and a similar force is required to actuate an associated brake locking arrangement. These mechanical braking systems also require a relatively large force to release the brake lock. A further disadvantage resulting from the relatively large operating forces required to actuate and/or release mechanical braking systems is the need for high strength structural components to withstand continued service without associated maintenance problems.
To overcome the requirement for relatively large forces to actuate the service and/or parking brake mechanisms in mechanical brake systems, electrically actuated hydraulic brake lock systems have been developed which require relatively minimal operator force to actuate. Such systems have found particular use on heavy duty utility vehicles, such as waste collection trucks, but are relatively expensive. Thus, a need exists for an economical and reliable brake lock system which may be readily utilized with a primary service brake system on a wheeled vehicle, and which is relatively simple to actuate during braking and subsequent release to enable movement of the vehicle.